This invention is related to the field of latching mechanisms and, more particularly, is related to the field of latching mechanisms which prevent the opening of a cover or guard over a movable or rotatable member, such as a centrifuge rotor, when it is moving.
An extremely important safety consideration with respect to the operation of a centrifuge or any other high speed moving member is to prevent the opening of the cover while the device is still moving. Because items such as rotors are moving at extremely high speeds, an inadvertent contact with the rotor during its operation could result in serious harm. Although it would be an extremely remote possibility, the opening of the centrifuge cover while the rotor is spinning might expose the operator to an extreme safety hazard if, while the cover is open, sample holding test tubes sitting within the rotor should break, sending fragmented pieces out of the centrifuge at high speed.
Several prior art devices have addressed the problem of establishing a motion sensing safety lock to secure a cover over a rotatable member. However, such prior art arrangements typically incorporate a very complex and undesirable multitude of parts to achieve a satisfactory, but expensive safety lock. Incorporated within several of these prior art arrangements is some type of contact member which is designed to engage the rotatable member in order to sense its mode of operation. However, these contact members utilize a complicated design of a plunger element which is spring biased within a movable cylinder, so that contact with the rotatable member, when it is rotating, will cause the contact member to tilt or move in a certain direction to prevent a latching device from allowing the opening of the cover.
Some of the prior art approaches utilize a more expensive and complex electrical circuitry arrangement to insure that the rotatable member is completely stopped before the cover can be opened. Other prior art devices incorporate a simple power disengaging switch for cutting off the power when the cover is opened. However, this does not completely solve the problem, since the rotatable member may still be rotating or coasting at high speed when the cover is opened. Substantially all of the prior art sensing arrangements utilize an unnecessarily complicated mechanism adjacent the rotating member that must be interconnected through some type of connecting means to the latching device that controls the opening of the cover or guard. These complicated structures require a significant amount of space within the overall machine and unnecessarily contribute to a larger machine.
In some instances the machine may be rather small for table top use, requiring a small uncomplicated, but dependable sensing device to be connected to the latching mechanism for preventing the opening of the cover or guard during the rotating movement of the rotatable member.